Metal truss assemblies have been widely used as structural members in building construction, and particularly in metal and high rise buildings. The metal truss assemblies are used for roof and floor structural framing on which the floor and roof materials are fastened. A roof or floor truss assembly generally comprise a top chord member and bottom chord member, with various web members running between them.
In roof truss assemblies, the ends of the top chord are secured to opposite ends of the bottom chord to form the perimeter of the roof truss with the roof peak formed by the top chord between. In floor truss assemblies, the top and bottom chords are positioned substantially in parallel. In both roof and floor truss assemblies, one or more web members span between and interconnect the top and bottom chords with at their end portions secured to the top chord(s) and to the bottom chord(s).
When erected in building frames, a plurality of the floor or roof truss assemblies position in parallel spanning the wall structures of the building and fixed to the top of bearing wall support frames. With floor trusses assemblies, the sub-roof and floor materials are then assembled across the top chords, and with roof truss assemblies, ceiling material may be fastened across the bottom chords and roof material may be fastened across the top chords. The reactions resulting from the combined roof loads and wind loads, plus the dead loads of the roof truss assemblies and roof and other transferred loads by the truss assemblies to the top of bearing wall support frames.
Various types of metal truss assemblies are available which require additional support members or brackets to attach together the chord and web members. Additionally, the chord and web members are assembled in a back-to-back orientation. Alternatively, the web members may fit within the chord member along a weak axis orientation. These known designs have a number of disadvantages including increased material and labor, more shipping volume, problems with stacking and higher cost.
There is a need to provide a cost competitive light weight easily assembled metal roof truss assembly yet still be structurally sufficient to withstand various loads. Disclosed is a metal truss assembly comprising:
a plurality of C-shape structural members including at least one chord member and two or more adjacent web members, each structural member having a base and two opposing flanges;
the at least one C-shape chord member having flanges extending from each side of the base with one flange having cutouts to receive two C-shape web members with a part of said flange of said chord member in place between said cutouts; and
each said C-shape web member placed into one of the cutouts in said flange to intersect the at least one chord member with the bases of the two C-shape web members adjacent the base of the at least one chord member.
In any case, the bases of each of the two or more adjacent web members and the at least one chord member may have the same width and the part of the chord flange between the two web members may be a cutout with a length that is less than the width of each of the adjacent web members. The two or more adjacent web members may intersect the at least one chord member at different angles. The part of the chord flange forming a cutout between web members may have a length of at least 1½ inches measured at the base of the at least one chord member.
The C-shape structural members may be easily assembled by directly attaching together the bases of chords and webs from one side. The C-shape structural members may be formed from a light gauge metal. Each C-shape structural member may have a lip on each flange extending inwardly from the flange. The lip of the part of the chord flange may have a length of at least ⅜ inches extending inwardly from the flange.
In assembly, each C-shape chord and web member may have a centerline axis and pilot holes may be provided in the base along the centerline axis of each web and chord member to provide alignment in assembly of chord and web members. The pilot holes in the web members are aligned and secured with fasteners to the at least one chord for orientation.
The metal truss assembly may further include a gusset plate for securing the two or more adjacent web members to the at least one chord member.
The metal truss assembly may further include a first line of markers which are provided in the base of each C-shape web member located inwardly a first distance from a free edge of an end of each of the C-shape web members to mark fastener locations for assembly with fasteners. A second line of markers may be located inwardly a second distance from an edge of the cutout of one C-shape chord member where the web member is to be assembled to mark fastener locations for assembly. At least two fasteners may be placed along each of the first distance and the second distance. The at least two fasteners placed along each of the first distance and the second distance may form a trapezoid and additional fasteners may be optionally provided in the trapezoid as desired. The first distance and the second distance may be the same, and may both be at least 9/16th inches. The first line of markers and the second line of markers may indicate the location of screw holes.
An alignment hole may be located at the intersection of the midpoint of the width of the at least one chord member and the midpoint of the width of one of the adjacent web members.
At least some of the C-shape members of the metal truss assembly may include joint markings in accordance to a computer program of the desired metal truss assembly to provide for ease of assembly at the assembly location. At least some of the C-shape members may further include fastener markings in accordance to a computer program of the desired metal truss assembly to provide for ease of assembly at the assembly location. The gusset plate may also include fastener markings in accordance to a computer program of the desired metal truss assembly to provide for ease of assembly at the assembly location.
At least some of the C-shape members of the metal truss assembly may be pre-partially cut in accordance to a computer program of the desired metal truss assembly so that bundles of the plurality of C-shape members can be sent to an assembly location and be subsequently separated for assembly of the metal truss assembly in accordance with the computer program thereof. Some of the C-shape members may be pre-partially cut through the opposing flanges of each C-shape member. Some of the C-shape members may be further pre-partially cut through a portion of the base of each C-shape member.
Also disclosed is metal truss assembly, comprising:
a plurality of C-shape structural members including a first chord member, a second chord member and at least two web members, each structural member having a base and two opposing flanges having opposite end portions; and
each C-shape chord member having at least two spaced apart chord cutouts and a chord flange with each cutout to receive one of the C-shape web members on assembly of the web members with the chord members forming an intersection of chord members and web members with the bases on the chord members and web members directly attached.
The assembly of the web members with the chord members form an intersection of chord members and web members with the bases on the chord members and web members directly attached. The first chord member may be substantially parallel to the second chord member. Alternatively, the first chord member may be traverse to the second chord member.
In any case, the bases of the chord members may have the same width. The part of the chord flange between two cutouts may have a length that is less than the width of each of the web members on assembly. Alternatively, the part of the chord flange between adjacent cutouts may have a length that is greater than the width of each of the adjacent web members on assembly. In yet another embodiment, the part of the chord flange between the cutouts may each have a length that is less than a width of any one of the bases of each of the two or more adjacent web members and the at least one chord member. The two or more adjacent web members may intersect a chord member at different angles. The two or more adjacent web members may also intersect a second chord member at different angles. The part of the chord flange between the two cutouts may have a length of at least 1½ inches measured at the base of the chord member. The length of part of the chord flange may be at least 1½ inches.
The C-shape structural members may be easily assembled by directly attaching together the bases of chords and webs from one side. The C-shape structural members may be formed from light gauge metal. Each C-shape structural member may have a lip on each flange extending inwardly from the flange. The lip of the part of the chord flange between the two cutouts may have a length of at least ⅜ inches extending inwardly from the flange.
In assembly, each C-shape web member may have a centerline axis and pilot holes may be provided in the base along the centerline axis of each web and chord member to provide alignment in assembly of the first chord member and the second chord member. The pilot holes in the web members may be aligned and secured with fasteners to the first and second chord members for orientation.
The metal truss assembly may further include at least one gusset plate for securing the two or more web members to one of the first chord member and the second chord member.
The metal truss assembly may further include a first line of markers which are provided in the base of each C-shape web member located inwardly a first distance from a free edge of an end of each of the C-shape web members to mark fastener locations for assembly with fasteners. A second line of markers may be located inwardly a second distance from an edge of the cutout of one C-shape chord member where the web member is to be assembled to mark fastener locations for assembly. At least two fasteners may be placed along each of the first distance and the second distance. The at least two fasteners placed along each of the first distance and the second distance may form a trapezoid and optionally providing additional fasteners in the trapezoid as desired. The first distance and the second distance may be the same, and may both be at least 9/16th inches. The first line of markers and the second line of markers may indicate the location of screw holes.
An alignment hole may be located at the intersection of the midpoint of the width of the chord member and the midpoint of the width of one of the web members.
The foregoing and other objects, features and advantages of the invention will be apparent from the following more detailed descriptions of particular embodiments of the invention, as illustrated in the accompanying drawing wherein like reference numbers represent like parts of the invention.